This applications relates to the art of vacuum cleaners and, more particularly, to vacuum cleaners that are capable of picking up liquid and separating same from an air stream that carries the liquid. The invention is particularly applicable to a wet pickup attachment for vacuum cleaners and will be described with specific reference thereto. However, it will be appreciated that the invention has broader aspects and that features of the invention may be used in other wet pickup devices as well as in air/liquid separators that are used for other purposes.
Wet pickup attachments for vacuum cleaners usually have a float operated valve that closes in response to a predetermined liquid level in a collection tank for preventing aspiration of liquid into the vacuum cleaner. Any malfunction of the float operated valve may cause liquid to be aspirated into the vacuum cleaner and cause damage. Therefore, it would be desirable to have a backup arrangement for blocking the flow of moisture laden air into the vacuum cleaner in the event of a malfunction in the float operated valve.
A wet pickup vacuum cleaner attachment in accordance with the present application includes an air/liquid separator having a collection tank and an exhaust passage. The exhaust passage has normally open primary and secondary exhaust openings that are closable by primary and secondary float operated valves in response to the liquid level in the collection tank.
In the event the primary float operated valve fails to close the primary exhaust opening in response to a predetermined liquid level in the collection tank, the accumulation of additional liquid in the tank will operate the secondary float operated valve to close the secondary exhaust opening.
In accordance with one arrangement, a hollow guide sleeve within the separator chamber has the primary float operated valve slidably guided internally thereof and the secondary float operated valve slidably guided externally thereof.
The primary float operated valve is operable to close the primary exhaust opening in response to a first liquid level in the collection tank, and the secondary float operated valve is operable to close the secondary exhaust opening in response to a second liquid level in the collection tank that is greater than the first liquid level. The primary and secondary exhaust openings are in series so that closing of one opening stops movement of air through both openings.
In one arrangement, the secondary float operated valve includes a valve member having a plurality of downwardly open float tubes depending therefrom. In accordance with another aspect of the application, the primary float operated valve includes a primary float having a plurality of holes therethrough for receiving the float tubes on the secondary float operated valve. The clearance between the holes and float tubes is sufficient to provide relative movement between the primary and secondary floats.
In accordance with another aspect of the application, a valve support member for the float operated valves includes a central guide sleeve, and inner and outer annular walls surrounding the guide sleeve. The inner periphery of the outer annular wall and the outer periphery of the inner annular wall are vertically spaced from one another to provide an outwardly facing annular outlet opening through which air flows outwardly from the separation chamber. A shield member positioned between the valve support member and the primary exhaust opening deflects the air flow in an opposite direction back toward the primary exhaust opening.
It is a principal object of the present invention to provide an improved air/liquid separator having two independent float operated valves.
It is another object of the invention to provide an improved wet pickup attachment for vacuum cleaners.
It is another object of the invention to provide an air/liquid separator having a float operated valve that includes a valve member having a plurality of spaced-apart downwardly open float tubes depending therefrom.
It is also an object of the invention to provide an air/liquid separator with a valve support member having an outwardly facing annular outlet opening therein between inner and outer annular walls.
It is an additional object of the invention to provide an air/liquid separator wherein a hollow guide sleeve has a primary float operated valve slidably guided internally thereof and a secondary float operated valve slidably guided externally thereof.